1. Field of the Invention
The present invention relates to a method for reclaiming aggregate from concrete waste material and a system therefor, which are capable of separating high quality aggregate such as gravel, crushed stones and sand from concrete waste material produced in construction sites to reclaim the same.
2. Description of the Related Art
Conventionally, concrete waste lumps produced in construction cites have been crushed and recycled as roadbed material or back filling material. However, they have only limited uses, so, the concrete waste lumps which had not been recycled have been abandoned. This causes a problem in the disposal of industrial wastes.
The above concrete waste lumps include aggregate such as gravel, crushed stones and sand, unreacted cement or the like, which cause difficulty in recycling the concrete waste lumps. To overcome this difficulty, sufficient removal of mortar attached to aggregate is required. This requirement, however, has not been satisfied as yet so that effective recycle of the aggregate, unreacted cement, or the like has not been performed up to the present.
To solve these problems, there have been proposed several methods. One example of these methods is disclosed in Japanese Patent application laid-open No. Hei 5-170498. With this method, concrete waste lumps are compression-crushed and sorted by size thereof, and then dry-crumbled and re-crushed at high density under high pressure to peel mortar from aggregate of the concrete waste lumps and separate mortar from the aggregate. However, only by the dry-crumbling technique, mortar cannot be peeled from the aggregate sufficiently, whereby the resultant aggregate do not conform to a legal standard. To conform the resultant aggregate to the legal standard, it must be mixed with a virgin material. This makes it difficult to reclaim high quality aggregate such as gravel, crushed stones and sand, which is solely usable, so as to cause various problems.